The NP is a programmable chip for network data message processing, which has low price and high flexibility like a general processor, and has high performance and extendibility like an Application Specific Integrated Circuit (ASIC), and is regarded as the core technology of the next generation network development.
To meet the requirement of high-speed lookup, the method of updating a routing table in the NP have been presented in recent years, one is locking routing lookup, table by only software is not applicable any more. Two methods for updating a routing namely stopping lookup before updating a routing table, and restarting the routing lookup until an update of router is completed, however, since the time of locking is long, such method causes longer time of lookup blocking; another method is updating entries during routing lookup, however, such method will cause a conflict between lookup and update of an access entry memory, and result in packet error or packet loss during lookup.
Thus, the methods for updating a routing table in the NP in the prior art causes either long time of lookup blocking or packet error or packet loss.